Ballistic panel and procedure to obtain it

ABSTRACT

A ballistic panel and procedure to obtain it, for applying it to bullet-proof vests, made of multiple synthetic fiber layers presenting at least one first flexible area and at least one second compact and rigid area.

STATE OF THE ART OF THE INVENTION

1. Field of Invention

The present invention is related to the field of provisions, techniques and products used for protecting and/or isolating spaces and persons against impacts, ballistic attacks, explosion fragments and others, and more specifically refers to a ballistic panel for armoring buildings, vehicles, clothing and personal protection items, ballistic vests, anti-shock panels, and others. Even though the panel is called “ballistic” its function is not restricted to stopping firearm projectiles and even when the product is described in connection to a body armor, it is clear that the panel is used for protecting buildings, vehicles and persons in general.

2. Description of Previous Art

The use of protection panels against all types of weapon attacks, including firearms, is increasingly expanding, in the search for protection of private and official vehicles, and these panels are permanently improved for application in body armor items.

Protection panels, generally ballistic, include metal and ceramic materials which make them heavy and rigid and thus limit their usefulness in armor applications for vehicles such as money carriers, since their weight is significantly increased, which renders them economically inefficient. These panels are obviously an obstacle when used in body armor such as ballistic vests and clothing manufacturing.

Bullet-proof vests are personal body armor items which absorb the impact of projectiles shot at the torso of the individuals wearing them and of fragments produced by explosions. The vests are made of several layers of laminated fibers or synthetic fabric and protect the person wearing them from projectiles shot by firearms and from the shrapnel of some hand-grenades. When guaranteed protection against rifle projectiles is needed, metal or ceramic plates are usually added. Thus, vests of varying protection degrees are manufactured by combining more or less dense woven fabrics with metal or ceramic plates: protection from handgun bullets, knives, rifles, fragments, etc. A vest may also include loin protection, shoulder pads, neck pads and lateral protective padding. But in general, vests include a front panel for breast protection and a back panel for back protection.

Both the front and back panels are made of layers or plates of flexible and light-weight fabrics, such as fabrics made of synthetic fibers such as aramids, polyester, fiberglass, nylon and others, which have been used with relative efficiency for the manufacturing of ballistic protection clothing, such as bullet-proof vests, but which have shown that the effectiveness-weight trade-off has proved once again to be a significant factor. Among the best known fabrics for ballistic vest manufacturing we find woven or unwoven fabrics known by their trademarks Kevlar® and Dyneema®. Other commercial fabrics similar to Kevlar® are those known by their trademarks Twaron®, Technora®, Artec®, and Heracron®. These materials are part of the polyaramid family. These fabrics are heat-resistant and do not reach the thermoplastic state at high temperatures, but degrade or directly burn.

Kevlar® or terephthalamide polyparaphenylene is a polyamide created by DuPont and is highly resistant. There are two types of Kevlar fiber, Kevlar 29 and Kevlar 49. Kevlar 29 is typically used in reinforcement applications due to its good mechanical properties or for fabrics, for example in the manufacturing of cables, resistant (protection) clothing or bullet-proof vests.

Dyneema® is a polyethylene of ultra-high molecular weight and is a fiber derived of a process known as “gel-spinning” where the polymer is spinned in molten state to form fibers with its polymeric chains aligned in the fibre. Another product of the polyethylene family such as Dyneema® is Spectra®. Unlike polyaramides, these fabrics reach the thermoplastic state under certain temperatures.

These fabrics have worked and still work relatively well when combined in layers to stop handgun projectiles. In this application the weight of the large number of fabrics or layers is still acceptable. Nevertheless, if the vest is meant to protect against war projectiles, the so-called fire arms, the necessary number of fabrics or layers make it very difficult to apply in wearable vests.

Besides stopping the projectile, the ballistic panel is also required to prevent the tremendous impact of the projectile from transferring to the user's body. A bullet may well be stopped by the package of layers which make up the ballistic panel but perhaps the impact of the bullet, depending on its caliber and energy, may impact vital parts of the person's torso. A powerful bullet may be stopped by the fabric package but if it impacts on the breastbone or heart area it may kill the person because of the shock energy transferred to the breast. Even though there are trauma protection materials combined with the highly resistant fabrics or plates placed inside the ballistic package, these trauma packs may work well with low-caliber projectiles but not with more powerful ones.

Since it would not be reasonable to add an exaggerated number of layers or fabrics to further buffer the trauma of the ballistic shock, because the fabric pack would be too heavy and large to be worn by an individual, the solution was using a small number of fabrics in the lower area to cover non-vital body parts, enough to stop the projectile and allow the shock energy to transfer to the body. These areas of the panel cover the sides and surrounding areas of vital organs. However, protection of vital organs such as heart and kidneys has been attained through adding metal or ceramic plates, which not only make the vest too heavy but also shatter when hit by more than one projectile.

On the other hand, the large number of high-resistance layers or fabrics mentioned above are part of a ballistic package which must be compact, that is, there can be no moving of the fabrics because if they slip out of place they would leave areas with fewer layers than others. These areas, which are thinner if some layers have slipped, would be weakened, without the required resistance. For this purpose, the layers are fixed by sewing them with high-resistance thread. The stitch where the thread pierces the fabric is an open orifice in the ballistic package. Since two threads go through each stitch and since those threads are strained, the orifice is slightly expanded. Any expert technician knows that this spot is extremely vulnerable, and a bullet could go through it, opening and piercing the threads, if impacted on that precise spot. That is why manufacturers try to have the least number of stitches possible, but there is always a necessary minimum to keep fabric layers together.

In the area of ballistic panel and bullet-proof vest development it would be very positive to have new technology and materials which allow for manufacturing safe and lightweight protection clothing and panels, which include the smallest number of stitches or none at all and which, besides being effective at stopping projectiles, do not transfer the impact to the user wearing a bullet-proof vest.

BRIEF DESCRIPTION OF THE INVENTION

Therefore the purpose of this invention is providing a panel for protecting spaces, objects and persons, such as protection clothing offering different protection levels in different areas, at least with one flexible area and one cohesive area, preferably rigid and compact, capable of stopping the projectile and also of preventing the impact energy from transferring to the user's body in the case of bullet-proof vests.

Another purpose of the present invention is providing a panel for manufacturing body armor with at least one flexible area and at least one rigid and compact area capable of stopping a projectile and also of preventing the impact energy from transferring to the user's body in the case of bullet-proof vest manufacturing, where the rigid and compact area is shaped so as to adjust to the person's body.

Another purpose of the present invention is providing a ballistic panel made up of multiple layers formed by natural or synthetic fibers, where the panel includes at least one first area where the layers form a flexible pack, and at least one second area where the layers are stuck to each other forming a compact and rigid pack, which renders stitches to keep the layers in place unnecessary.

Yet another purpose of the present invention is providing a ballistic panel for protecting objects, spaces and persons, such as those used in armor packages and bullet-proof vests, made up by multiple layers formed by natural or synthetic fibers, where the panel includes at least one first area where said layers are connected among themselves in a flexible pack, and at least one second area where said layers are stuck together forming a cohesive and rigid pack.

Yet another purpose of the present invention is providing a procedure for obtaining a ballistic panel which includes the following steps:

Providing multiple layers of temperature-sensitive fibers,

Placing the layers one on top of the other,

Defining at least one second area, and

Applying heat and pressure on at least one second area so as to thermally stick the layers together at least in one second area to form said cohesive and rigid pack.

BRIEF DESCRIPTION OF DRAWINGS

For the sake of clarity and a better understanding of the purpose of the present invention, the latter has been represented in several figures, where the invention has been featured in the preferred design, by way of example, where:

FIG. 1 shows a perspective view of a ballistic panel, front or back, made up by multiple layers, as in a ballistic package of fabric layers, including a trauma pack and a separate area as described for the invention;

FIG. 2 shows the enlarged view of two layers of the vest shown in FIG. 1, at the time of manufacturing;

FIG. 3 shows the cross section of the vest shown in FIG. 1 along cut line III-III;

FIG. 4 shows the enlarged view of two layers of the vest shown in FIG. 1, during an alternative manufacturing procedure;

FIG. 5 shows a perspective view of a panel showing an alternative to the invention;

FIG. 6 shows a cross section of the vest in FIG. 5 along cut line VI-VI.

FIG. 7 shows a cross section of a panel showing another alternative to the invention, and

FIG. 8 shows a cross section of a panel showing yet another alternative to the invention.

DETAILED DESCRIPTION OF THE INVENTION

In reference to the figures, we see that the invention includes a ballistic panel identified in FIG. 1 under general reference 1. Panel 1 can be used for the protection of objects, spaces and persons, as well as for armors, and is preferably designed for the manufacturing of bullet-proof vests. Panel 1 is made up by multiple layers 2, indicated as 2 a, . . . 2 n, for example 12, 24 or more layers, and at least one trauma pack 3 which may be optional and if used may be placed between the last layers 2, closer to the user's body or directly as a last layer, as shown on FIG. 1. Layers 2 may be made of natural or synthetic fibers, and preferably with flexible fabrics or plates made of synthetic fibers and/or woven fabrics.

Yarns and fabrics sold under the trademarks Kevlar® and Dyneema® are well known in this field. As explained above, Kevlar® is a polyamide, terephthalamide polyparaphenylene, sold by DuPont and Dyneema® is a polyethylene of ultra-high molecular weight. Both fabrics are highly resistant and are therefore efficacious in ballistic applications and protection against sharp impacts, fragments, etc.

Panel 1, as explained above, is shaped to cover the front and/or back of the user's torso, with a higher cut 4 to adjust to the user's neck and side cuts 5 to pass under the arm-pit and allow the front or back to flex so that the sides 7 can bend under the arms and cover the sides of the torso. This design pattern is repeated for the panel covering the users's back and both panels, front and back, are placed, as known in the industry, adjusted and fixed firmly within a pocket with zips, and fasteners, velcro, etc. needed to make the vest to be worn and fixed to the torso. Fabric layers 2 in panel 1 may be fixed together, for example by means of fasteners or stitching 8 which are necessary to keep the fabrics fixed together but without their losing their flexibility as a whole, which allows them to adjust to the user's torso. Stitching might not be necessary if the fabric package is temporarily fixed by other means until the fabrics are finally fixed together, as described below.

The number of layers 2 grouped together in a package as shown, can efficiently stop a projectile but the impact energy of the shot, even when the projectile has been stopped, could transfer to the user's body generating damages or death if the projectile is very powerful and hits vital organs, as shown in dotted lines in panel 1 and identified as 9. Sometimes trauma pack 3 may suffice to absorb the mentioned mechanical energy impact but when it is known to be insufficient for certain projectiles or weapons to be faced, area 9 may be covered, in a conventional vest, with a metal or ceramic plate, obviously adding considerable weight to the vest.

In the invention, vital area 9, which may have any design shape, will be formed and/or made up of specific properties thanks to the concepts on which the invention is based. Thus, the vest will have at least one first area formed by all those areas of the vest outside area 9, where layers 2 a, . . . , 2 n, are connected together, forming a flexible pack; and at least one second area, corresponding to area 9, where said layers are firmly glued together forming a preferably compact and rigid pack. That is, area 9 is at least one because there may be one or more areas 9 for protecting different vital organs, for example, the heart with the front panel and the kidneys with the back one. Even though area 9 has been represented with a triangular shape, the design of area 9 could vary according to the kind of protection needed.

Layers 2 a, . . . , 2 n may include layers or plates made of natural or synthetic fibers, which may be woven or unwoven fabrics. Preferably, they will be synthetic fibers, though they may be fabrics of different characteristics such as Kevlar® and Dyneema®. In any of these two cases, at least one second area 9, made up by layers 2 of the panel, are technically fixed together.

When terephthalamide polyparaphenylene fiber fabrics are used (such as Kevlar®), such thermal adhesion between the layers is given by fusion and cohesion of adjacent layers 2 with a polyethylene plate 10 placed between each layer 2, best shown in FIG. 2. Plate 10 may also be replaced by a polymeric adhesive, known as “hot melt”, which may be applied in any known way. FIG. 3 shows a cross section of the vest through cut line III-III, where one may see layers 2 a, . . . , 2 n which have been stuck together in area 9 and thermally fixed through plate 10 or an adhesive layer, so as to form a rigid and compact pack which is per se a plate with better resistance or ballistic characteristics and/or an actual trauma pack, without the need to add heavier plates, such as ceramic plates. Since the layers are fixed together in area 9, less stitching will be needed, if any at all, since the layers are fixed in area 9. That is, the fabrics will not move and the panel will have better ballistic qualities and will weigh the same, without needing to add any plates or additional materials.

Alternatively, since each fabric layer 2 includes polyethylene fiber fabric of ultra-high molecular weight (such as Dyneema®), said thermal adhesion between the layers to form a the rigid and compact area 9, is attained by means of fusion and cohesion of pressed fibers in adjacent fabrics at least in one second area. This fusion is obtained, as designed in the invention, by placing plate which has a window or hole 12, shown in FIG. 4, following a procedure described below.

According to another method for manufacturing this invention, the ballistic panel of FIG. 5 presents all the characteristics of panel 1, made of multiple fabric layers 2 a, . . . , 2 n, which may or may not include a trauma plate, but, unlike the manufacturing method for FIG. 1, the panel in FIG. 5, under reference 13, has a rigid and compact area 9, shaped to adjust to the user's body. Thus, the rigid and compact area, identified under reference 14 in FIGS. 5 and 6, is shaped to adjust to the femenine user's breast, something which no vest had offered to date, providing the necessary safety of the flexible panel and improved ballistic qualities and trauma protection with the necessary rigidity and cohesion while adjusting to the body shape for increased comfort. In all cases, areas 9 and 14 will include fixed fabrics, making stitching less necessary or unnecessary, besides offering the mentioned trauma protection and improving the ballistic characteristics of the panel or pack.

FIGS. 7 and 8 show other alternatives to the invention with formed, cohesive and preferably rigid and compact areas, which form recesses on one or both sides of the panel. FIG. 7 shows a panel also made of several 2 a to 2 n layers which, according to the invention, presents one or more cohesive, preferably rigid and compact areas, 15 a to 15 n. Areas 15 may form recesses 16 on the side in touch with the user's body or on the side facing the shots or fragments. It has been proved that areas 15 may have any predetermined shape and may be placed according to a general pattern, which leads to improved ballistic qualities for the panel. Areas 17 placed between adjacent areas 15 prove to have better ballistic performance since the fabric layers are fixed on their edges defined by adjacent areas 15 a and 15N, as shown on FIG. 7.

FIG. 8 shows a cross section similar to FIG. 7, where the panel offers the same general characteristics than the panel on FIG. 7, where cohesive, preferably rigid and compact areas are indicated as 18 a and 18 n and, unlike areas 15 on FIG. 7, areas 18 define recesses 19 and 20, on both sides of the panel. Areas 21 are placed between adjacent areas 18 and offer better ballistic performance, as is the case with areas 17 on FIG. 7.

In connection to any of the described and illustrated panels, it is important to point out that the latter may be combined within a single vest, even overlapping and without the need to fix them, since the vest may be designed with receptacles or pockets for holding them. The invention also foresees the possibility of recesses 15 and/or 16 to be alternated on both sides of the panel, for example, a recess on one side and an adjacent recess on the other.

According to another aspect of the invention, there are at least two different procedures for manufacturing the described ballistic panels, depending on the type of fabric used for the vest. Thus, the first procedure may be used for making panels with terephthalamide polyparaphenylene fiber fabric (such as Kevlar®), which method includes the steps below:

Providing multiple layers or fabrics of temperature-sensitive fibers. Even though FIG. 2 shows only two fabrics, 2 a, 2 b, it is obvious that all the layers of the panel should be placed there.

Then, placing said layers or fabrics one on top of the other, as shown in FIG. 2.

Defining at least one second area, for example following the design shown on FIGS. 1 and 2.

And finally applying heat and pressure on at least one second area 9 so as to thermally stick said fabrics together at least in one second area to form a rigid and compact pack. In the case of terephthalamide polyparaphenylene fabric, which cannot be directly and thermally stuck together, this step of applying heat and pressure is attained by placing a hot-melt plate, for example a polyethylene plate 10, between each fabric and on second area 9, which will be thermally modified to become rigid and compact so as to provide trauma protection. Plate 10 may be polyethylene of ultra-high molecular weight but also polyurethane of higher molecular weight, but more elastic. Polyvinyl butyral may also be used and in general any thermoplastic material such as PVC and even polyester which reaches thermoplastic state at the desired temperatures during the process. Again, the temperature and pressure values depend on the material used.

When the fabrics are polyethylene fibers of ultra-high molecular weight (such as Dyneema®), the fabrics are heat-sensitive and it is not necessary to use a hot-melt plate such as plate 10. Instead, during the process of applying heat and pressure, a heat-resistant plate 11 is used between each one of the layers 2 a, . . . , 2 n, and each layer 11 has a cut 12 shaped as second area 9, which allows heat and pressure to stick the fabrics together through cuts 12. Preferably, plate 11 will be a heat-resistant polyester plate applied to take Dyneema® fabrics to their thermoplastic state and thus generate adhesion between them, except on plates 11. Plates 11 may be pre-cut or punched to be easily removed once the fusion and sticking of fabric layers 2 is over. Even though FIG. 4 shows only two layers 2 a and 2 b it is obvious that in the procedure all the fabric layers which are part of the panel will be placed together. Of course, all plates 11 will be placed so that cuts 12 coincide to form a second rigid and compact pack. Once the necessary heat and pressure to render layers in area 9 compact and rigid, plates 11 may be easily removed.

Every time the present description and claims point to the need to apply heat and pressure, these values will depend on the type of materials used. For example, in terms of pressure, it may be positive if a press under pressure is applied on regions 9 and 14 or it may be negative if the fabric pack, with plates 10 or 11, is put inside an airtight bag and is treated inside an autoclave. By way of example, we may say the temperature of the procedure will be higher than 80° C. and may reach 300° C., but preferably it will not exceed 150° C. The highest temperature threshold will be that which suffices to take the desired materials to their thermoplastic state without reaching thermal degradation. When “pressure” is indicated, we mean a pressure condition. For example, it may be positive pressure applied through a press, or negative pressure which sticks the fabrics together in an autoclave, or a combination of both, that is, applying positive pressure to a fabric pack inside an autoclave with negative pressure.

In both procedures used for hot-melt plate 10 and plate 11, the step of applying heat and pressure may include the use of a matrix to deform the second rigid and compact area and to form area 14, shown on FIG. 5 and shaped to adjust to the user of the bullet-proof vest which includes the panel, in the case, for example, of the breast of a feminine user. In order to make the panel as designed on FIGS. 7 and 8, it is possible to use matrixes with projections and/or recesses which allow for defining the recesses on one or both sides of the panel.

In any case, the described panel is very comfortable without losing the capability of stopping the projectile and of providing trauma protection, with a flexible part which adjusts to the body where so much trauma protection is not needed and with modified parts, without adding plates or additional weight, so as to offer the desired trauma protection for specific body parts. Thus the vests manufactured with the described panel are lightweight and flexible, while resistant and capable of absorbing all types of punctual impacts.

The panel of the invention has been tested both for stopping projectiles, such as very powerful handgun projectiles, and for war weapons, where the results have been surprisingly positive.

In summary, the described panel stops the projectile and provides trauma protection, without needing to place a rigid barrier of maximum resistance with solid materials and serious structural manufacturing problems, such as ceramics, which given its fragility, shatters when hit by dynamic impact. 

Having thus specially described and determined the nature of the present invention and the way the latter should be manufactured, we claim to hold property and exclusive rights upon:
 1. A ballistic panel to be applied for the protection of objects, spaces and persons, such as the construction of armors and bullet-proof vests, made up of multiple layers made of natural or synthetic fibers, the panel comprising: at least one first area where these layers are connected together forming a flexible pack, and at least one second area where these layers are stuck together in a cohesive and rigid pack.
 2. The panel of claim 1, wherein the at least one second area is formed into a compact and rigid pack.
 3. The panel of claim 2, wherein it is part of a bullet-proof vest and the at least one second area which is formed into the compact and rigid pack is defined in coincidence with at least one area of the user's body where a vital organ is.
 4. The panel of claim 3, wherein the at least one second area formed into a compact and rigid pack presents a shape which adjusts to the torso of the individual wearing the vest.
 5. The panel of claim 4, wherein the individual wearing the vest is a female user and the mentioned shape adjusts to the user's breast size.
 6. The panel of claim 1, wherein the at least one first area is formed by the panel layers which are only sewn together.
 7. The panel of claim 1, wherein the at least one second area is formed by the panel layers which are thermally stuck together.
 8. The panel of claim 7, wherein each one of said layers includes a terephthalamide polyparaphenylene fiber fabric, and said thermal adhesion between layers is attained by fusion and cohesion of a material selected between a polyethylene plate and a layer of polymeric adhesive, placed between each layer.
 9. The panel of claim 8, wherein each one of said layers includes polyethylene fiber fabric of ultra-high molecular weight, and said thermal adhesion between the layers is attained by means of fusion and cohesion through pressure applied to fibers of two adjacent layers on said at least one second area.
 10. The panel of claim 1, wherein each one of said layers is a fabric chosen between woven or unwoven fabric.
 11. The panel of claim 1, wherein the at least one second area made up by the rigid and compact pack includes multiple areas, each one protecting a different vital organ of the individual wearing the vest with at least two ballistic panels.
 12. The panel of claim 1, wherein the at least one second area forms a recess on at least one side of said panel.
 13. A method for obtaining a ballistic panel for the protection of objects, spaces and persons, such as the construction of armors and bullet-proof vests, made up of multiple layers made of natural or synthetic fibers, the panel comprising: at least one first area where these layers are connected together forming a flexible pack, and at least one second area where these layers are stuck together in a cohesive and rigid pack, wherein the method comprises the steps of: providing multiple layers of temperature-sensitive fibers, placing those layers one on top of the other, defining at least one second area, and applying heat and pressure on at least one second area so as to thermally stick those layers together in the at least one second area to form a cohesive and rigid pack.
 14. The method of claim 13, wherein the step of applying heat and pressure is attained by placing a hot-melt plate between each one of the layers and matching it with the at least one second area.
 15. The method of claim 14, wherein said hot-melt plate is a polyethylene film.
 16. The method of claim 15, wherein each layer includes a terephthalamide polyparaphenylene fiber fabric.
 17. The method of claim 13, wherein the step of applying heat and pressure is followed by placing a heat-resistant plate between each layer, each plate with a cut which defines the at least one second area, while all plates are placed so that said cuts coincide with the at least one second area.
 18. The method of claim 17, wherein said heat-resistant plate is a polyester plate.
 19. The method of claim 18, wherein each one of the layers includes polyethylene fiber fabric of ultra-high molecular weight.
 20. The method of claim 13, wherein each step of applying heat and pressure includes deforming the at least one second area to adjust its shape to the body of the individual wearing the bullet-proof vest which includes the panel. 